| 摘要 |
A centrally locatable castor, particularly for hospital beds, with a fixing pin for mounting at the foot of a bed and carrying a castor fork and a roller by means of a ball bearing, having a polyhedral adjusting bolt which is carried axially through and non-rotatably in the fixing pin and which can be moved axially by means of a central adjusting linkage against the influence of a counter-spring which urges the bolt towards it upper position, the adjusting bolt having at its bottom end an adjusting disc projecting into the castor fork and engaging at a predetermined position of the adjusting bolt with a direction control member which prevents displacement due to swivelling and engaging at the lowest position with a brake unit freely mounted in the fork for preventing both displacement by swivelling and also movement of the roller, wherein a brake unit is provided which encloses an adjusting disc below and at the side and also encloses a counter-disc located under and arranged for engagement with the adjusting disc, a retaining spring being arranged for holding the brake unit and being located in a position of constant contact with either the back of the castor fork or the adjusting disc. |
